The overall objective of the research is to define a system for decontaminating platelet concentrates. The desired method would reduce the risk of viral infection and bacterial sepsis associated with therapeutic use of platelet concentrates. Present screening of donated blood will not detect all potentially infectious contaminants. Therefore it is important to find a means of rendering blood products non-specifically non-infectious. We propose to demonstrate our ability to inactivate a model animal virus in platelet concentrates. We will examine the effects of the inactivation treatment on 1) gross platelet morphology by measuring platelet count as a function of inactivation time; 2) response of platelets to aggregating agents; and 3) platelet activation by fluorescent antibody assay. This research has the potential to be commercially useful in safeguarding the estimated 5 to 7 million units of platelets transfused annually.